Snow cannon
A snow cannon is a device used to make artificial snow. It relies on atomizing water with compressed air and allowing it to condense into snow. This device is often used by ski hills and ski resorts to supplement naturally occurring snow and extend the skiing season.
A snow cannon usually consists of a water nozzle onto which a high pressure jet of air is blown. Water flows from the nozzle and the jet of air causes the water to break up into tiny droplets (almost a fog). If the surrounding air temperature is near or below freezing, the droplets of water tend to evaporate and rapidly cool. This method only works when the ambient air is at 0°C (32°F) or lower.
If the humidity is low, artificial snow can be made when the temperature is as high as 1.1°C (34°F). This is possible because of the rapid evaporation and evaporative cooling caused by the low humidity.